docs: def getall(self, key, default=_marker):
          """Return a list of all values matching the key."""
          identity = self._title(key)
          res = [v for i, k, v in self._impl._items if i == identity]
          if res:
              return res
          if not res and default is not _marker:
              return default
          raise KeyError('Key not found: %r' % key)